Mapping Soil Erosion Risk Using RUSLE, GIS, Remote Sensing Methods: A Case of Mountainous Sub-watershed, Ifni Lake and High Valley of Tifnoute (High Moroccan Atlas)

It is important to combine different methods to quantify the soil loss in a mountainous sub-watershed. Geographic Information System (GIS), Remote Sensing and Revised Universal SoilLoss Equation (RUSLE) were adopted to estimate the annual soil loss in the highest watershed inMorocco. The High valley of Tifnoute is a part of a national park of Toubkal and constitutes a best choice for such application. The availability of some ecological resources (Lake ifni) and the population that suffers from yearly loss of their agricultural areas constitute a primary need for erosion mapping, which make it’s the first one in the study area. The deterioration of ecological heritage and agricultural fields by sediment filling are the major problems in the study area.The RUSLE factors (R, K, LS, C and P) were computed using Tropical Rainfall Measuring Mission (TRMM), soil analysis, topographic map, remote sensing and digital elevation model (DEM). The resultant map of annual soil erosion with RUSLE method show a real problem of soil loss in the study area, and high soil erosion zones are located in the middle and in upstream of the watershed. The sediments transported constitues a big problem for Ifni lake located in downstream of the sub-watershed. The article highlights the application of RUSLE, GIS and RS methods in the mapping of annual soil loss estimation in mountainous area. The results constitue an essential database to offer a planning of conservation practices to control soil erosion.